The Origin of the Elements

I just love this particular lecture.  

I wonder how dense the universe was when matter ceased to form.

This is because I suspect that in the first iteration the first star was a very huge star, so big in fact that it burned for only seconds, Unfortunately for any such vision a black hole of unimaginable proportions would be formed such that, I have to guess, that galaxy formation would all but cease to exist.  It is indeed puzzling that there isn't much thought given to how the density of the universe aged and therefore how big or small the first stars might have been and/or when they formed as the universe expanded and cooled.  Oh well, I'll continue to keep an eye out for answers to such questions.